Composite refractory member



Dec. 3, 1963 o. M. WICKEN 3,112,921

COMPOSITE REFRACTORY MEMBER Filed May 4, 1962 K E 20 j INVENTOR. 0:29;: mare/v (wake/v 147 TOR/VF United States Patent M 3,112,921 COMPOSITE REFRACTORY MEMBER Oscar Milton Wicken, Pittsburgh, Pa., assignor to Harbison-Walker Refractories Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed May 4, 1962, Ser. No. 192,582 12 Claims. (Cl. 263-46) This invention relates to refractory linings and more particularly to refractory linings for tubular kilns and refractory members useful for forming such linings.

It is well known and understood in the art that tubular kilns, such as rotary kilns, can be lined with refractory blocks. Non-acid or basic refractory brick are conventionally used for this purpose, and generally include some manner of oxidizable metal plate between adjacent brick in order to prevent cracking or spalling. In practice, however, the campaign life of such linings is frequently limited by relatively small areas of accelerated wear. Very often, it will be necessary to shut down the kiln, and completely reconstruct and repair the lining when but minor portions have eroded or worn away.

Such failures may occur for various reasonsamong them improper installation of the lining, and uneven bonding between brick from which the lining is fabricated. It has been suggested that special shims and the like be included to key proper installation. Others have suggested fabricating the lining of a plurality of layers of different types of brick for improved bonding.

Laminated structures of this latter type, of course, increase the complexity of actual fabrication of the lining since more than one type of brick must be handled, with commensurate increase in labor and cost.

Still others have suggested that the crux of the fabrication of a good rotary kiln lining is the allowance for expansion between the rings or courses of brick which form the lining. Combustible sheets of material such as paper, etc., have been used, as by attachment, to upper and/or lower ends of brick and adjacent rings, which sheets burn out during initial operation of the kiln, and thereby provide a space for subsequent expansion between them.

Of course, difficulties arise in initially assuring good attachment between the combustible sheets of material and the refractory brick. Good attachment is necessary to assure each brick installed in the lining includes the combustible sheet. If some brick are accidentally installed without a sheet, problems of uneven expansion can result. Further, the necessity of the extra step of gluing or otherwise attaching a sheet of combustible material to a face or faces of brick increases the cost of production.

Accordingly, it is an object of this invention to provide improved refractory linings. Another object of this invention is to provide improved composite refractory shapes particularly suited for fabrication of the lining of a tubular kiln.

It is yet another object of this invention to provide an improved metal cased refractory brick particularly suited for fabrication of rotary kiln linings, the metal case of which is a one-piece unit which serves the multiple functions of allowing expansion between tiers or rings of a rotary kiln lining upon heating, and which, installed, provides both circumferential and longitudinal reinforcement of the lining.

Briefly, in one embodiment, a rotary kiln lining, according to the concepts of this invention, as fabricated of a plurality of rings of partially cased basic (non-acid) refractory brick. These brick are normally wedge-shaped for easier fabrication of circular courses or rings. Each brick is provided with a one-piece metal case. The metal case is so fabricated as to at least partially cover three adjacent sides of the brick which form one corner of the hot face. The cases are further so constructed and ar- 3,1 12,921 Patented Dec. 3, 1963 ranged as to allow relative expansion between brick which form a ring, and to provide an overall longitudinal and circumferential metal reinforcing web for the lining.

A better understanding, further features, and other objects and advantages of this invention will become obvious to those skilled in the art from the following detailed description with reference to the appended drawings. In these drawings:

FIG. 1 is an isometric View of a brick used in fabricating a rotary kiln lining according to the concepts of this invention; 1

FIG. 2 is a top view of one ring of a rotary kiln lining fabricated of the brick of FIG. 1;

FIG. 3 is a fragmentary perspective view of a longitudinal section of a rotary kiln lining fabricated of the brick of FIG. 1 showing the circumferential and longitudinal interrelation between brick; and

FIG. 3a is an enlarged, fragmentary, perspective view of a portion of the lining of FIG. 3.

For rotary kiln linings, refractory brick of this invention can be made of any non-acid refractory. Exemplary non-acid refractories well known to those skilled in the art include magnesite, periclase, chromite, magnesiachrome, chorrne-magnesia, various magnesia spinels, mixtures of the foregoing, and the like. They may be fired or unfired, synthetically bonded, fused, etc.

In the drawings, a generally polygonal, wedge-shaped brick or block is shown since that is what is conventionally used in a rotary kiln lining, but it should be understood that the invention is equally applicable to other shapes used for fabricating various other refractory structures well known to those skilled in the art. Also the brick may be of other than a non-acid refractory depending on the service installation intended. The unitary metal case for brick according to this invention, may be fabricated of substantially any oxidizable metal. Those metals conventionally accepted for this purpose are iron or steel. The gauge or thickness of the plate will depend upon the installation in which it is to be used.

Referring now to the drawings, a refractory brick, according to the concepts of this invention, includes a generally polygonal, wedge-shaped non-acid refractory body 10 partially encompassed by a novel metal case unit 11. The block or body 10 includes a plurality of sides extending between a pair of opposed faces 13 and 13a. Opposed,

substantially parallel brick faces 13 and 13a serve as the hot face and cold face, respectively. In essence, the metal case is a 3-part unit and includes the relatively large metal plate 12, which substantially entirely covers one of the large faces of the block 10, but terminates just short of the rear or cold face 13a thereof. The edge portion 14 of the plate 12 adjacent hot face 13 is bent at right angles so as to partially cover the hot face substantially along its long edge. Another portion 15 of the plate 12 is bent at right angles thereto and to edge portion 14 so as to sub stantially cover the face 16 of block 10. Thus, the case can be characterized as a one-piece unit bent parallel to two intersecting edges to form a flat sheet having two flanges extending from the same side of the sheet. The portion 15 terminates inwardly of the cold face 1311 a distance substantially equal to the spacing of the plate 12 therefrom. It is likewise spaced inwardly of the other large face 17 of the block. The case may be initially attached to the brick by any of the well known techniques such as gluing, punching ears from the case into the green brick, co-molding, etc. Thus, the metal case 11 is an integral unit comprised of three planar metal sections 12,

14 and 15, bent to lie contiguously over at least a portion of an end of the block 19. The plate 12 is notched at 19 to a depth equal to the depth of the exposed area 18 of block face 16. The plate 14, which is an extension of plate 12, cooperates therewith and with plate 15 to thus expose the corner 20. The notching exposes an appreciable, as distinguished from negligible, portion of the two sides and face which form the corner 20. This exposed corner, and the exposed portion 18 of face 16, provide a breather space in a service installation allowing for radial expansion of the metal case commensurate with volume gain upon heating and oxidation, and provides room for melted metal flow adjacent the hot face without causing disruption of the lining. More important, this pocket-like notch collects metal which flows and prevents its deposition on the hot face. Furthermore, this allowance for oxidation expansion and metal flow promotes a positive fusing longitudinally between juxtaposed brick in adjacent rings as schematically indicated at 25 in FIG. 3, as well as assuring a more firm circumferential metal bonding, as schematically indicated at 26, between adjacent brick of the same ring. In FIG. 3a the general areas of fusing, 25 and 26, are more clearly indicated in dashed lines. Most of this longitudinal and circumferential fusing will occur about and over the exposed corner 20 of the block 10, and in cooperation with the other brick units which make up the lining provides a metal framework or web which reinforces the lining both longitudinally and circumferentially within the outer kiln shell 40.

The side portion 15 has an expansion crimp 30 formed adjacent its hot face edge. The crimp 3t) tapers from its maximum height adjacent the hot face to a point intermediate the ends of plate 15. Preferably, it will terminate about /3 the length of plate 15 from its hot face edge. This crimp 3% provides all the space necessary for longitudinal expansion between rings, and cooperates with the breather space above discussed to provide a more flexible, self-adjusting, yet strong and serviceable, rotary kiln lining. The crimp provides the self-adjusting feature because of its relative compressibility and continuous contact with an adjacent brick during heating and cooling of the kiln. The use of the crimp further does away with the necessity of incorporating some extraneous combustible material which has been previously utilized for this purpose.

In the foregoing discussion, reference to hot face, of course, describes that brick face which is exposed to the interior of the kiln, and the cold face describes that face of the brick furthest removed from the hot face.

While a preferred embodiment of the invention has been shown in the drawings and described in detail above, it should be understood that various modifications may be had which would be equally within the spirit and scope of the invention, and that the true measure of the invention is as defined in the hereafter set forth claims.

I claim:

1. A composite refractory member comprising, a refractory block which includes a plurality of sides extending between a pair of opposed faces, and a plurality of corners, each corner formed by the intersection of two sides and one face, a metal case attached to the block, said case being a one-piece unit bent parallel to two intersecting edges to form a flat sheet with two flanges extending from the same side of the sheet and so arranged as to cover an appreciable portion of two sides and one face of the block which intersect to form a common corner of the block, and the portions of the case adjacent said common corner being cut away to expose a minor but appreciable portion of the sides and face which form said common corner.

2. A composite refractory member comprising, a refractory block which includes a plurality of sides extending between a pair of opposed, parallel faces, and a plurality of corners, each corner formed by the intersection of two sides and one face, a one-piece metal case attached to the block, said case being a one-piece unit bent parallel to two intersecting edges to form a flat sheet with two flanges extending from the same side of the sheet and so arranged as to cover an appreciable portion of two sides and one d face of the block which intersect to form a common corner of the block, and the portions of the case adjacent said common corner being cut away to expose a minor but appreciable portion of the sides and face which form said common corner.

3. A composite basic refractory member comprising, a refractory block which includes a plurality of sides extending between a pair of opposed faces and a plurality of corners, each corner formed by the intersection of two sides and one face, a one-piece metal case attached to the block, said case being a one-piece unit bent parallel to two intersecting edges to form a flat sheet with two flanges extending from the same side of the sheet and so arranged as to cover an appreciable portion of two sides and only a minor portion of one face of the block which intersect to form a common corner of the block, and the portions of the case adjacent said common corner being cutaway to expose a minor but appreciable portion of the sides and face which form said common corner.

4. The member of claim 3 in which the portion of the case which covers only a minor portion of one face, extends substantially the entire length of said one face, and in which one of the flanges covers side of the block but terminates below the said one face.

5. The member of claim 4 in which a spacing crimp is formed in the flange which terminates below the said one face.

6. A kiln comprising, a tubular metal shell and a lining disposed Within the shell, said lining comprised of a plurality of courses of refractory members, each of said members being a refractory block which includes a plurality of sides extending between a pair of opposed faces, and a plurality of corners, each corner formed by the intersection of two sides and one face, a metal case attached to the block, said case being a one-piece unit bent parallel to two intersecting edges to form a flat sheet with two flanges extending from the same side of the sheet and so arranged as to cover an appreciable portion of two sides and one face of the block which intersect to form a common corner of the block, and the portions of the case adjacent said common corner being cut away to expose a minor but appreciable portion of the sides and face which form said common corner, the other of the pair of opposed faces of each of the refractory members being positioned adjacent the tubular shell to form a lining therefor.

7. A kiln comprising, a tubular metal shell and a lining disposed within the shell, said lining comprised of a plurality of courses of refractory members, each of said members being a refractory block which includes a plurality of sides extending between a pair of opposed faces, and a plurality of corners, each corner formed by the intersection of two sides and one face, a metal case attached to the block, said case being a one-piece unit bent parallel to two intersecting edges to form a flat sheet with two flanges extending from the same side of the sheet and so arranged as to cover an appreciable portion of two sides and one face of the block which intersect to form a common corner of the block, and the portions of the case adjacent said common corner being cut away to expose a minor but appreciable portion of the sides and face which form said common corner, one of the flange portions of each of the cases covering a side of the block to which it is attached but terminating below the said one face, and having an outward crimp formed therein in abutting relation with an adjacent surface of another refractory member within the tubular shell, the other of the pair of opposed faces of each of the refractory members being positioned adjacent the tubular shell to form a lining therefor.

'8. A kiln comprising, a tubular metal shell and a lining disposed within the shell, said lining comprised of a plurality of courses of refractory members, each of said members being a non-acid refractory block which includes a plurality of sides extending between a pair of opposed faces, and a plurality of corners, each corner formed by the intersection of two sides and one face, a metal case attached to the block, said case being a one-piece unit bent parallel to two intersecting edges to form a fiat sheet with two flanges extending from the same side of the sheet and so arranged as to cover an appreciable portion of two sides and one face of the block which intersect to form a common corner of the block, and the portions of the case adjacent said common corner being cut away to expose a minor but appreciable portion of the sides and face which form said common corner, the other of the pair of opposed faces of each of the refractory members being positioned adjacent the tubular shell to form a lining therefor.

9. The kin of claim 8 in which each of the blocks is wedge-shaped and in which the larger of the opposed faces of the wedge shape is disposed adjacent the inner surface of the tubular shell.

10. The kiln of claim 8 in which the kiln is a rotary kiln.

11. The kiln of claim 8 in which the cases of adjacent blocks in each course, and the cases of juxtaposed blocks in adjacent courses are united by means, which means is the result of cases of adjacent members fusing together.

12. The kiln of claim 11 in which the means is at least partially over the said common corners of the respective rerractory members.

References Cited in the file of this patent UNITED STATES PATENTS 2,192,642 Grifiith Mar. 5, 1940 2,829,877 Davis Apr. 8, 1958 2,853,872 Samuel Sept. 30, 1958 2,915,893 Wilkins Dec. 8, 1959 2,982,237 Copeland et a1. May 2, 19 61 

1. A COMPOSITE REFRACTORY MEMBER COMPRISING, A REFRACTORY BLOCK WHICH INCLUDES A PLURALITY OF SIDES EXTENDING BETWEEN A PAIR OF OPPOSED FACES, AND A PLURALITY OF CORNERS, EACH CORNER FORMED BY THE INTERSECTION OF TWO SIDES AND ONE FACE, A METAL CASE ATTCHED TO THE BLOCK, SAID CASE BEING A ONE-PIECE UNIT BENT PARALLEL TO TWO INTERSECTING 